Recently, vehicle-to-vehicle (V2V) communications have become one of the practical and popular technologies frequently applied in vehicle safety systems. The V2V technology includes but is not limited to intersection movement assistance (IMA), emergency electronic brake lights (EEBL), left-turn assistant (LTA), and forward collision warning (FCW). Among the causes of traffic accidents in recent years, distracted driving resulting from drivers whose attention is diverted from the road is the top cause, and the second and third causes are failure to yield in accordance with relevant regulations and drunk driving. The LTA technology alerts the drivers to other vehicles coming up in the blind spots as well as lowers the incidence rate of the traffic accidents caused by distracted driving.
The LTA can be categorized into a front LTA and a rear LTA. The front LTA can transmit a turn signal through a controller area network (CAN) bus to detect a driver's intent to make turns. When the driver turns on the left-turn signal and detects an approaching vehicle that comes from an opposite direction, the front LTA sends a left-turn alarm to alert other vehicles to the driver's intent to make a left turn. The rear LTA, however, cannot transmit the turn signal through the CAN bus and can merely send an alarm to alert other approaching vehicles after detecting the vehicles. Compared to the front LTA, the rear LTA can be installed in a simple and rapid manner, whereas the rear LTA cannot allow the vehicle to capture the message sent by the front LTA and thus can merely send the left-turn alarm through vehicular ad-hoc network. Accordingly, the rear LTA is very much likely to issue erroneous alarms. In view of the above, how to reduce the erroneous alarms sent by the rear LTA is one of the concerns to be addressed while the vehicular ad-hoc network is applied.